Methods of detecting bonding between a bonding wire and a bonding location on a wire bonding machine

ABSTRACT

A method of determining a bonding status between a wire and at least one bonding location of a workpiece is provided. The method includes the steps of: (a) bonding a portion of a wire to a bonding location of a workpiece using a bonding tool of a wire bonding machine; (b) determining a motion profile of the bonding tool for determining if the portion of the wire is bonded to the bonding location, the motion profile being configured to result in the wire being broken during the motion profile if the portion of the wire is not bonded to the bonding location; and (c) moving the bonding tool along the motion profile to determine if the portion of the wire is bonded to the bonding location. Other methods of determining a bonding status between a wire and at least one bonding location of a workpiece are also provided.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication No. 62/857,027 filed Jun. 4, 2019, the contents of which areincorporated herein by reference.

FIELD

The invention relates to the formation of wire loops and other wirebonded structures, and more particularly, to improved methods ofdetecting the status of a bonded portion of a wire.

BACKGROUND

In the processing and packaging of semiconductor devices, wire bonding(e.g., ball bonding, wedge bonding, etc.) continues to be a widely usedmethod of providing electrical interconnection between locations withina package (e.g., between a die pad of a semiconductor die and a lead ofa leadframe). More specifically, using a wire bonder (also known as awire bonding machine) wire loops are formed between respective locationsto be electrically interconnected.

An exemplary conventional wire bonding sequence (using ball bondingtechniques) of a simple wire loop includes: (1) forming a free air ballon an end of a wire extending from a bonding tool; (2) forming a firstbond of a wire loop on a die pad of a semiconductor die using the freeair ball; (3) extending a length of wire in a desired shape between thedie pad and a lead of a leadframe; (4) stitch bonding the wire to thelead of the leadframe to form a second bond of the wire loop; and (5)severing the supply wire from the now formed wire loop. In forming thebonds between (a) the ends of the wire loop and (b) the bond site (e.g.,a die pad, a lead, etc.) varying types of bonding energy may be usedincluding, for example, ultrasonic energy, thermosonic energy,thermocompressive energy, amongst others.

In connection with wire bonding, it is often desirable to confirm that aportion of wire is properly bonded to a bonding location. Wire bondingmachines marketed by Kulicke and Soffa Industries, Inc. often utilize a“BITS” process (i.e., bond integrity test system) to confirm that properwire bonds have been formed. International Patent ApplicationPublication WO 2009/002345, which is incorporated by reference herein inits entirety, illustrates exemplary details of such processes andrelated systems.

Thus, it would be desirable to provide improved methods of determining abonding status of a portion of a wire loop (e.g., to determine if theportion of the wire loop is properly bonded to a bonding location).

SUMMARY

According to an exemplary embodiment of the invention, a method ofdetermining a bonding status between a wire and at least one bondinglocation of a workpiece is provided. The method includes the steps of:(a) bonding a portion of a wire to a bonding location of a workpieceusing a bonding tool of a wire bonding machine; (b) determining a motionprofile of the bonding tool (thus providing a predetermined motionprofile) for determining if the portion of the wire is bonded to thebonding location, the motion profile being configured to result in thewire being broken during the motion profile if the portion of the wireis not bonded to the bonding location; and (c) moving the bonding toolalong the motion profile to determine if the portion of the wire isbonded to the bonding location.

Such methods may be used to check the bonding status of a plurality ofportions of the wire bonded to a corresponding plurality of bondinglocations of the workpiece. In such an event, steps (b) and (c)described in the prior paragraph may be repeated for each of theplurality of portions of the wire to determine if each of the pluralityof portions of the wire are bonded to their corresponding bondinglocation of the workpiece.

According to another exemplary embodiment of the invention, anothermethod of determining a bonding status between a wire and at least onebonding location of a workpiece is provided. The method includes thesteps of: (a) bonding a portion of a wire to a bonding location of aworkpiece using a bonding tool of a wire bonding machine; (b) detecting,during step (a), at least two of (i) a deformation characteristicrelated to bonding the portion of wire, (ii) a bond force characteristicrelated to bonding the portion of wire, and (iii) a transducercharacteristic of a transducer of the wire bonding machine; and (c)determining a bonding status of the portion of the wire that was bondedto the bonding location in step (a) using information detected in step(b).

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is best understood from the following detailed descriptionwhen read in connection with the accompanying drawings. It is emphasizedthat, according to common practice, the various features of the drawingsare not to scale. On the contrary, the dimensions of the variousfeatures are arbitrarily expanded or reduced for clarity. Included inthe drawings are the following figures:

FIGS. 1A-1H are a series of block diagram views of a wire bondingsystem, illustrating a method of determining that a bonded portion ofwire is bonded to a bonding location, in accordance with an exemplaryembodiment of the invention;

FIGS. 2A-2F are a series of block diagram views of a wire bondingsystem, illustrating a method of determining that a bonded portion ofwire is not bonded to a bonding location, in accordance with anexemplary embodiment of the invention;

FIG. 3 is a block diagram of a conventional wire bonding machine usefulfor illustrating certain exemplary methods in accordance with theinvention; and

FIG. 4 is a flow diagram illustrating exemplary methods of determining abonding status of a portion of wire bonded to a bonding location on awire bonding machine in accordance with various exemplary embodiments ofthe invention.

DETAILED DESCRIPTION

According to certain exemplary embodiments of the invention, real timebond lift detection for workpieces (e.g., semiconductor devices such asmemory based semiconductor devices, stacked-die memory devices, etc.) isprovided. In such memory based semiconductor devices, a portion of wiremay be configured to be at least one of a power lead or a ground lead ofthe memory based semiconductor device.

Aspects of the invention are particularly applicable tomulti-stitch-bonding processes (i.e., wire loops including more than twobonded portions—for example, wire loops including three, four, five, ormore bonded portions). For multi-stitch die-to-die bonding, detectingstitch bond lifts can be difficult since die to die impedance is verylow.

Aspects of the invention will force a bonding wire to break if the bondis not stuck properly on a bonding location. Detecting the broken wirecan be accomplished using existing detection systems (e.g., a BITSsystem) that detect electrical continuity (or a lack of electricalcontinuity). Such detection is easy for a broken wire which exhibits ahigh impedance, making clear that the wire is not secure to the properbonding location.

Thus, the determination of whether the wire is broken may be made usinga detection system of the wire bonding machine. For example, thedetection system detects whether a conductive path is establishedbetween (a) the wire, and (b) a portion of the wire bonding machine. Theconductive path includes at least one of (a) a wire clamp for clampingthe wire, (b) a wire spool for supplying the wire to the bonding tool,(c) a diverter element for assisting in positioning of the wire betweenthe wire spool and the bonding tool, and (d) an air guide system forassisting in positioning of the wire between the wire spool and thebonding tool. The detection system may detect whether the conductivepath is established by detecting at least one of (a) a predeterminedcurrent flow in the conductive path, (b) a predetermined change incapacitance between the conductive path and a ground connection of thewire bonding machine, and (c) a predetermined phase shift of currentflowing in the conductive path.

According to certain exemplary embodiments of the invention, methods ofdetermining/detecting a bonding status (e.g., if a portion of wire isproperly bonded, if a portion of wire is not properly bonded, etc.) of awire bond connection on a workpiece are provided. For example, suchmethods may be performed in real time on a production wire bondingsystem (e.g., a wire bonding machine).

Referring now to FIGS. 1A-1H, a wire bonding system 100 is provided.Wire bonding system 100 includes a support structure 102 (e.g., a heatblock, an anvil, etc.) for supporting a workpiece 103. As shown in FIG.1A, workpiece 103 includes a substrate 104, and a plurality of stackedsemiconductor die 106 a, 106 b, and 106 c.

In FIGS. 1A-1H, wire bonding system 100 also includes wire bonding tool108 (e.g., a capillary wire bonding tool), a wire clamp 110, and adetection system 114 (e.g., a BITS system). A length of wire 112 isprovided to wire bonding tool 108 through wire clamp 110. In FIG. 1A, afree air ball 112 a (i.e., a portion of wire 112) is seated at the tipof wire bonding tool 108. Referring to FIG. 1E, an electrical connection113 is provided between wire clamp 110 and detection system 114. As isknown to those skilled in the art, using detection system 114, with wireclamp 110 in a closed position as shown in FIG. 1E, electricalcontinuity may be detected between detection system 114 and a portion ofwire bonded to workpiece 103.

Using various methods of the invention, real-time feedback regarding thethe bonding status of a portion of a wire loop (or other portion of wiresuch as a conductive bump) may be provided to the wire bonding system.

In FIG. 1A, free air ball 112 a is bonded to a bonding location (e.g., adie pad) of die 106 c. At FIG. 1B, free air ball 112 a has beentransformed to bonded wire portion 112 b. Also at FIG. 1B, a portion ofwire 112 is extended from bonded wire portion 112 b and bonding tool108. As FIG. 1C, wire 112 has further been shaped to include kink 112 c,and another wire bond is being formed between wire 112 and a bondinglocation of die 106 b. At FIG. 1D, this wire bond is shown as bondedwire portion 112 d, and another length of wire 112 extends from bondedwire portion 112 d to bonding tool 108 including kink 112 e.

At this time, it is desirable to determine the bonding status of bondedwire portion 112 d (e.g., if bonded wire portion 112 d is properlybonded to a bonding location of die 106 b). Thus, as shown in FIG. 1E,with wire clamp 110 in a closed position, wire bonding tool 108 is movedalong a predetermined motion profile (where the motion profile mayinclude a predetermined directions, distances, angles, etc.) (see dottedline bonding tool 108 having moved along the motion profile, stretchingthe wire as shown in the dotted line, but not disrupting bonded wireportion 112 d). Thus, as shown in FIG. 1E, bonded wire portion 112 d isstill properly bonded to a bonding location of die 106 b, as is detectedusing detection system 114. At FIGS. 1F-1G, the remainder of a wire loop(labelled as wire loop 116 in FIG. 1H), including bonded wire portion112 f, is formed.

FIGS. 2A-2F illustrate substantially similar elements as in FIGS. 1A-1H,but with a different result. As shown in FIG. 2E, bonded wire portion112 d (shown in FIG. 2D) did not stick to the bonding location of die106 b, or otherwise pulled away from the bonding location with thepredetermined motion profile (i.e., the dotted line arrow shown in FIG.2E). As bonding tool 108 moves further along the motion profile as shownin FIG. 2F, wire break 112 g occurs as detected by detection system 114.Because wire break 112 g is detected by detection system 114, thebonding status of bonded wire portion 112 d is known as “unacceptable”or “unbonded” or “lifted-off” or some similar status.

Thus, in FIGS. 1A-1H, it has been determined that bonded portion 112 dis bonded to a bonding location of die 106 b. In FIGS. 2A-2F, it hasbeen determined that bonded portion 112 d is not bonded to a bondinglocation of die 106 b.

In FIGS. 1A-1H and in FIGS. 2A-2F only one bonded portion (i.e., bondedportion 112 d) is checked using the inventive bonding status check.However, it is understood that mutliple bonded portions may be checkedusing the invention. For example, each bonded portion of wire loop 116shown in FIG. 1H (i.e., bonded wire portion 112 b, bonded portion 112 d,and bonded portion 112 f) may be checked using a motion profile such asthe motion profile shown and described in connection with FIG. 1E.

In a specific example, after formation of bonded wire portion 112 b (seeFIG. 1B) a predetermined motion profile may be used to check the bondingstatus of bonded wire portion 112 b. After checking the bonding statusof bonded wire portion 112 b, bonded portion 112 d may be formed (seeFIG. 1D). After formation of bonded portion 112 d, the predeterminedmotion profile of FIG. 1E may be used to check the bonding status ofbonded wire portion 112 d. After checking the bonding status of bondedwire portion 112 d, bonded portion 112 f may be formed (see FIG. 1G).After formation of bonded portion 112 f (but before separation of wireloop 116 from the wire source), a predetermined motion profile may beused to check the bonding status of bonded wire portion 112 f. Thus, itis clear that the inventive techniques described above in connectionwith FIGS. 1A-1H and FIGS. 2A-2F may be used to check the bonding statusof any number of bonded portions of a wire loop.

It will be appreciated that, in accordance with aspects of the invention(such as shown in FIGS. 1A-1H and FIGS. 2A-2F), a step of determining amotion profile of the bonding tool for determining if the portion of thewire is bonded to the bonding location may be included. That is, priorto forming a bonded portion of a wire loop (such as bonded portion 112 din FIG. 1D), a motion profile may be determined. That is, prior tofollowing the motion profile (as in FIG. 1E), the motion profile shouldbe determined. Such a motion profile may be configured to result in thewire being broken (e.g., see FIG. 2F) during the motion profile if theportion of the wire is not bonded to the bonding location. The motionprofile may be determined through a trial and error process (or otherprocess such as an iterative process), using information relevant to thespecific application (e.g., bonding locations of the various bondedportions of the wire loops, wire looping parameters, etc.).

FIGS. 1A-1H and FIGS. 2A-2F illustrate certain exemplary methods ofdetermining a bonding status of bonded portions of a wire (e.g., a wireloop) bonded to a workpiece. However, the invention contemplatesadditional methods of determining the bonding status of the bonded wireportions. As described below, in other exemplary embodiments of theinvention, information detected by a wire bonding machine (e.g., adeformation characteristic related to bonding a portion of wire, a bondforce characteristic related to bonding the portion of wire, atransducer characteristic of a transducer of the wire bonding machine,etc.) during a wire bonding process may also be used to determine abonding status between a wire and at least one bonding location of aworkpiece.

FIG. 3 is a side view of a simplified wire bonding machine 100 a (whichmay be similar to, or the same as, wire bonding machine 100 of FIGS.1A-1H) which may be used to detect the information described in theimmediately preceding paragraph, and in other parts of the presentapplication. Wire bonding machine 100 a includes support structure 102(e.g., a heat block, an anvil, etc.) for supporting a semiconductorelement 304 during a wire bonding operation. In the illustrated examplein FIG. 1A, semiconductor element 304 includes a plurality ofsemiconductor die 304 a on a leadframe 304 b. Of course, other types ofsemiconductor elements (e.g., such as memory based semiconductordevices, stacked die devices, among others) are contemplated within thescope of the invention.

Wire bonding machine 100 a also includes wire bonding tool 108 (e.g., acapillary wire bonding tool, etc.) for bonding wire portions tosemiconductor element 304. As will be appreciated by those skilled inthe art, wire bonding tool 108 (carried by bond head assembly 300) ismoveable along a plurality of axes of wire bonding machine 100 a toperform wire bonding operations. For example, wire bonding tool 108 ismoved along the x-axis and y-axis through movement of bond head assembly300. A linkage 300 a is carried by bond head assembly 300 and wirebonding tool 108. This linkage 110 a is configured for movement alongthe z-axis of wire bonding machine 100 a. Additional elements carried bybond head assembly 300 (and specifically carried by linkage 300 a)includes: a moveable portion of z-axis motor 300 a 1 which moves alongthe z-axis with linkage 300 a; a transducer 300 a 2 for carrying wirebonding tool 108, and for providing ultrasonic scrub to tip portion 108a of wire bonding tool 108; a force sensor 300 a 3 for sensing a bondingforce applied during wire bonding operations; and a z-axis positiondetector 300 a 4 (e.g., a z-axis encoder). As is known by those skilledin the art, z-axis position detector 300 a 4 detects the z-axis positionof linkage 300 a (and hence a relative z-axis position of bonding tool108), and provides data corresponding to this z-axis position (e.g.,real time) to computer 302 of wire bonding machine 100 a. Thus, computer302 has information related to the z-axis position of bonding tool 108through its motions. Certain information from each of z-axis motor 300 a1, transducer 300 a 2, force sensor 300 a 3, and z-axis positiondetector 300 a 4 may be provided to computer 302 (as shown by the arrowextending from bond head assembly 300 and computer 302). Computer 302may also provide information (e.g., instructions) back to elements ofbond head assembly 300 (as shown by the arrow extending from computer302 to bond head assembly 300). In a specific example, in a closed loopconfiguration, computer 302 provides control signals to one z-axis motor300 a 1 and/or transducer 300 a 2.

FIG. 4 is a flow diagram illustrating exemplary methods in accordancewith the invention. As is understood by those skilled in the art,certain steps included in the flow diagram may be omitted; certainadditional steps may be added; and the order of the steps may be alteredfrom the order illustrated—all within the scope of the invention.

FIG. 4 is a flow diagram illustrating exemplary methods of determining abonding status of a portion of wire bonded to a bonding location on awire bonding machine, such as wire bonding machine 100 of FIGS. 1A-1Hand FIGS. 2A-2F (or wire bonding machine 100 a of FIG. 3, or other wirebonding machines within the scope of the invention).

At Step 400, relationships are determined between (i) characteristics tobe detected during a wire bonding process, and (ii) a bonding status ofa portion of wire to be bonded to a workpiece. The characteristics mayinclude, for example, any two or more of: a deformation characteristicrelated to bonding the portion of wire; a bond force characteristicrelated to bonding the portion of wire; and a transducer characteristicof a transducer of the wire bonding machine. The bonding status mayinclude a simple status (e.g., “bonded” or “not bonded”), or may besomewhat more specific (e.g., a “good” bond, an “acceptable” bond, an“unacceptable” bond, “a lift off condition”, among other labels asdetermined by the user). Depending on the bonding status, operations maycontinue (e.g., in the case of a good bond or an acceptable bond),operations may stop (e.g., the wire bonding operation may stop in theevent of an “unacceptable” bond or a “lift off condition”), an alarm orother notification may be provided (e.g., in the case of acceptablebond, an unacceptable bond, a lift off condition, etc.), etc. Thespecific labels applied (the bonding status), and the action takenrelated to such a label (e.g., continuing wire bonding operations,stopping wire bonding operations, providing an alarm of othernotification, etc.), may be customized for the application and/or user.

In a more specific example, testing/experimentation may be done on oneor more wire bonding applications (e.g., using a specific die, specificwire, specific wire bonding parameters—which may be optimized using aclosed loop process, specific wire looping parameters—which may beoptimized using a closed loop process, etc.). Through thistesting/experimentation—values of the aforementioned characteristics(e.g., deformation characteristics, bond force characteristics,tranducer characteristics, etc.) may be detected and recorded. Variousranges for each of the characteristics, and combined ranges for themultiple characteristics, may be determined.

For example, a range for each bonding status (e.g., a good bond, anacceptable bond, an unacceptable bond, a lift off condition, etc.) maybe provided by the testing/experimentation. Likewise, each bondingstatus may be assigned to combined ranges of the characteristics.

In a specific example, let us assume that each of a deformationcharacteristic, a bond force characteristic, and a tranducercharacteristic is monitored. A “good bond” bonding status may be appliedto a situation when each of the three characteristics falls within apredetermined range for that characteristic. An “acceptable bond”bonding status may be applied when one or more of the threecharacteristics falls within a predetermined range for thatcharacteristic that is not in the “good” range, but is in an“acceptable” range. An “unacceptable bond” bonding status may be appliedwhen one or more of the three characteristics falls within apredetermined range for that characteristic that is not in the “good”range or the “acceptable” range, but is in an “unacceptable” range. Andso on.

At Step 402, a portion of a wire is bonded to a bonding location of aworkpiece using a bonding tool of a wire bonding machine. For example,FIG. 1F illustrates a bonded wire portion 112 d (of the to be formedwire loop 116, as shown in FIG. 1H) bonded to a bonding location of die106 b.

At Step 404 a, a deformation characteristic related to the bondedportion of wire is detected during Step 402. The deformationcharacteristic relates to a vertical deformation of the portion of wireduring Step 402, for example, as measured by a z-axis position detector(e.g., see z-axis position detector 300 a 4 in FIG. 3). The deformationmay be considered the measured deformation between (i) contact of thewire portion with the bonding location, and (ii) the completion of thebonding process of Step 402. The deformation characteristic may relateto single value (i.e., a single z-axis measurement/value) taken duringStep 402, or may relate to a series of values (i.e., a series ofmeasurements/values versus time, such as a deformation profile) takenduring Step 402.

At Step 404 b, a bond force characteristic related to bonding theportion of wire is detected. The bond force characteristic may relate toa bond force measured by at least one of (i) a force sensor in a bondhead of the wire bonding machine (e.g., see force sensor 300 a 3 in FIG.3), and (ii) a z-axis motor characteristic of a z-axis motor of the wirebonding machine (see z-axis motor 300 a 1 in FIG. 3). The bond forcecharacteristic may relate to single value (i.e., a single bond forcemeasurement/value) taken during Step 402, or may relate to a series ofvalues (i.e., a series of measurements/values versus time, such as abond force profile) taken during Step 402.

At Step 404 c, a transducer characteristic of a transducer of the wirebonding machine is detected. As will be appreciated by those skilled inthe art, a typical wire bonding machine includes an ultrasonictransducer carried by a bond head assembly. The ultrasonic transducertypically carries a wire bonding tool (e.g., see wire bonding tool 108in FIGS. 1A-1H), and applies an ultrasonic scrub to a tip portion of thewire bonding tool to bond wire portions to bonding locations. Inaccordance with the invention, the transducer characteristic may relateto any of a number of characteristics such as, for example: (i) animpedance of the transducer; and (ii) an electrical characteristic ofthe transducer (e.g., a voltage measurement, a current measurement,etc.). The transducer characteristic may relate to single value (i.e., asingle transducer measurement/value) taken during Step 402, or mayrelate to a series of values (i.e., a series of measurements/valuesversus time, such as a transducer profile) taken during Step 402.

At Step 406, a bonding status of the portion of the wire bonded to thebonding location in Step 402 is determined using information detected inat least two of Steps 404 a, 404 b, and 404 c (e.g., using thedeformation characteristic and the bond force characteristic, using thedeformation characteristic and the transducer characteristic, using thebond force characteristic and the transducer characteristic, using all 3of the deformation characteristic and the bond force characteristic andthe transducer characteristic). As described above, the bonding statusmay be a “good” bond, an “acceptable” bond, an “unacceptable” bond, a“lift off condition”, or any other bonding status.

At Step 408, a plurality of portions of the wire are bonded to acorresponding plurality of bonding locations of the workpiece, and Steps404 (including at least two of Steps 404 a, 404 b, and 404 c) and Step406 are repeated for each of the plurality of portions of the wire todetermine if each of the plurality of portions of the wire are bonded totheir corresponding bonding location of the workpiece. For example,referring to FIGS. 1A-1H, each of the wire bonded portions (i.e., wirebonded portions 112 b, 112 d, and 112 f) may be checked using Steps 404and 406, after formation of the specific wire bonded portion and beforeformation of the next wire bonded portion.

Although the invention is illustrated with respect to specificworkpieces, it is not limited thereto. That is, a stacked dieapplication of FIGS. 1A-1H and FIGS. 2A-2F, and the simple semiconductordie/leadftame application in FIG. 3, simply illustrate exemplaryworkpieces. Any type of workpiece may be utilized that incorporates wirebonding.

Although the invention has been illustrated with respect to certain wireloop shapes, it is not limited thereto. Aspects of the invention may beutilized to detect bonding (or non bonding, or another bonding status)of any wire portions such as, for example: stud bumps; simple wire loopsincluding a first bond and a second bond only; complex wire loopsincluding multiple tiers and devices; etc.

Further still, it should be understood that if a wire loop includesmultiple bonded portions, any or all of the bonded portions may bechecked for proper bonding utilizing aspects of the invention. Forexample, conventional techniques may be adequate to detect properbonding of certain bonded portions, while aspects of the invention maybe used for other bonded portions.

It will be appreciated that data related to the one or morecharacteristics may also be saved in memory (e.g., memory of the wirebonding machine, or remote memory) for later analysis (e.g., to confirmthe ranges for each bonding status are correct when analyzing specificworkpieces that have completed a wire bonding operation).

Although the invention is illustrated and described herein withreference to specific embodiments, the invention is not intended to belimited to the details shown. Rather, various modifications may be madein the details within the scope and range of equivalents of the claimsand without departing from the invention.

What is claimed:
 1. A method of determining a bonding status between awire and at least one bonding location of a workpiece, the methodcomprising the steps of: (a) bonding a portion of a wire to a bondinglocation of a workpiece using a bonding tool of a wire bonding machine;(b) determining a motion profile of the bonding tool for determining ifthe portion of the wire is bonded to the bonding location, the motionprofile being configured to result in the wire being broken during themotion profile if the portion of the wire is not bonded to the bondinglocation; and (c) moving the bonding tool along the motion profile todetermine if the portion of the wire is bonded to the bonding location.2. The method of claim 1 wherein the workpiece is a memory basedsemiconductor device.
 3. The method of claim 2 wherein the wire isconfigured to be at least one of a power lead or a ground lead of thememory based semiconductor device.
 4. The method of claim 1 wherein step(c) includes determining if the wire is broken during the motion profileto determine if the portion is bonded to the bonding location.
 5. Themethod of claim 4 wherein the determination of whether the wire isbroken is made using a detection system of the wire bonding machine, thedetection system detecting whether a conductive path is establishedbetween (a) the wire, and (b) a portion of the wire bonding machine. 6.The method of 5 wherein the conductive path includes at least one of (a)a wire clamp for clamping the wire, (b) a wire spool for supplying thewire to the bonding tool, (c) a diverter element for assisting inpositioning of the wire between the wire spool and the bonding tool, and(d) an air guide system for assisting in positioning of the wire betweenthe wire spool and the bonding tool.
 7. The method of claim 6 whereinthe detection system detects whether the conductive path is establishedby detecting at least one of (a) a predetermined current flow in theconductive path, (b) a predetermined change in capacitance between theconductive path and a ground connection of the wire bonding machine, and(c) a predetermined phase shift of current flowing in the conductivepath.
 8. The method of claim 1 wherein a plurality of portions of thewire are bonded to a corresponding plurality of bonding locations of theworkpiece, and wherein steps (b) and (c) are repeated for each of theplurality of portions of the wire to determine if each of the pluralityof portions of the wire are bonded to their corresponding bondinglocation of the workpiece.
 9. A method of determining a bonding statusbetween a wire and at least one bonding location of a workpiece, themethod comprising the steps of: (a) bonding a portion of a wire to abonding location of a workpiece using a bonding tool of a wire bondingmachine; (b) detecting, during step (a), at least two of (i) adeformation characteristic related to bonding the portion of wire, (ii)a bond force characteristic related to bonding the portion of wire, and(iii) a transducer characteristic of a transducer of the wire bondingmachine; and (c) determining a bonding status of the portion of the wirebonded to the bonding location in step (a) using information detected instep (b).
 10. The method of claim 9 wherein the workpiece is a memorybased semiconductor device.
 11. The method of claim 10 wherein the wireis configured to be at least one of a power lead or a ground lead of thememory based semiconductor device.
 12. The method of claim 9 wherein aplurality of portions of the wire are bonded to a correspondingplurality of bonding locations of the workpiece, and wherein steps (b)and (c) are repeated for each of the plurality of portions of the wireto determine if each of the plurality of portions of the wire are bondedto their corresponding bonding location of the workpiece.
 13. The methodof claim 9 wherein the information used in step (c) to determine if theportion of the wire is bonded to the bonding location includes thedeformation characteristic and the bond force characteristic.
 14. Themethod of claim 9 wherein the information used in step (c) to determineif the portion of the wire is bonded to the bonding location includesthe deformation characteristic and the transducer characteristic. 15.The method of claim 9 wherein the information used in step (c) todetermine if the portion of the wire is bonded to the bonding locationincludes the transducer characteristic and the bond forcecharacteristic.
 16. The method of claim 9 wherein the information usedin step (c) to determine if the portion of the wire is bonded to thebonding location includes the deformation characteristic, the bond forcecharacteristic, and the transducer characteristic.
 17. The method ofclaim 9 wherein the deformation characteristic relates to a verticaldeformation of the portion of wire during step (b) as measured by az-axis position detector.
 18. The method of claim 9 wherein the bondforce characteristic relates to a bond force measured by at least one of(i) a force sensor in a bond head of the wire bonding machine, and (ii)a z-axis motor characteristic of a z-axis motor of the wire bondingmachine.
 19. The method of claim 9 wherein the transducer characteristicrelates to at least one of (i) an impedance of the transducer, and (ii)an electrical characteristic of the transducer.
 20. The method of claim9 wherein the deformation characteristic relates to single valueobtained during step (b).
 21. The method of claim 9 wherein the bondforce characteristic relates to single value obtained during step (b).22. The method of claim 9 wherein the transducer characteristic relatesto single value obtained during step (b).
 23. The method of claim 9wherein the deformation characteristic relates to a series of valuesobtained during step (b).
 24. The method of claim 9 wherein the bondforce characteristic relates to a series of values obtained during step(b).
 25. The method of claim 9 wherein the transducer characteristicrelates to a series of values obtained during step (b).